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JSON Formatter & Validator

Format, beautify, and validate JSON data online. Instant client-side processing with syntax highlighting.

What is a JSON Formatter?

A JSON Formatter is an essential developer tool that takes raw, minified, or poorly structured JSON data and transforms it into a clean, readable format with proper indentation and syntax highlighting. Whether you’re debugging API responses, reviewing configuration files, or working with data from a database, a JSON formatter saves you time and reduces errors.

JSON (JavaScript Object Notation) has become the universal language for data exchange on the web. APIs return it, configuration files use it, and databases store it. But raw JSON — especially minified JSON — is nearly impossible to read. Our free online JSON formatter instantly beautifies your data, validates its structure, and highlights syntax errors so you can work confidently.

All processing happens directly in your browser. Your data never leaves your device, making this tool safe for sensitive information like API keys or user data.

How to Use This JSON Formatter

  1. Paste your JSON into the input text area — or type it manually
  2. Click “Format / Validate” to beautify the JSON with proper indentation
  3. Review the output — syntax errors will be flagged with the exact line and position
  4. Click “Minify” to compress JSON by removing all whitespace (useful for production)
  5. Click “Copy Output” to copy the result to your clipboard

Common Use Cases

  • Debugging API responses — Format raw JSON returned by REST or GraphQL APIs to quickly find the data you need
  • Validating configuration files — Catch syntax errors in package.json, tsconfig.json, or any JSON config before they cause build failures
  • Preparing test data — Format and validate JSON payloads before using them in Postman, cURL, or automated tests
  • Minifying for production — Compress JSON files to reduce payload size and improve application performance
  • Code reviews — Beautify JSON snippets in pull requests to make them easier to review

Frequently Asked Questions

What’s the difference between formatting and validating JSON?

Formatting (or beautifying) adds indentation and line breaks to make JSON readable. Validating checks whether the JSON follows correct syntax rules — matching braces, proper quoting, valid data types. Our tool does both simultaneously: if your JSON is valid, it formats it; if not, it tells you exactly where the error is.

Is it safe to paste sensitive data into this tool?

Yes. This JSON formatter runs entirely in your browser using JavaScript. Your data is never sent to any server. You can verify this by using the tool with your network tab open — no requests are made.

What’s the maximum JSON size this tool can handle?

The tool works well with JSON files up to several megabytes. For extremely large files (50MB+), consider using a local tool like jq on the command line.